Struct Regs 

pub struct Regs {
    pid: i32,
    orig: user_regs_struct,
    cur: user_regs_struct,
    scratch_used: u64,
}

Registers of a tracee stopped at syscall entry, with pending edits.

Fields

pid: i32

orig: user_regs_struct

cur: user_regs_struct

scratch_used: u64

Bytes already handed out below the red zone by Regs::alloc_stack.

Implementations

impl Regs

pub fn fetch(pid: i32) -> Result<Regs, i32>

Fetches the registers of pid.

pub fn pid(&self) -> i32

Thread id these registers belong to.

pub fn abi(&self) -> Abi

ABI the tracee made this syscall through.

pub fn sysnum(&self) -> i64

Syscall number being entered, in the tracee’s own ABI numbering.

pub fn fail(&mut self, errno: i32)

Skips the syscall and makes it fail with errno: a tracer that sets the number to -1 at the entry or seccomp stop has the tracee see whatever it put in the result register (seccomp(2), SECCOMP_RET_TRACE), which is ENOSYS left alone.

pub fn arg(&self, i: usize) -> u64

Syscall argument i (0..6), in the register order of the tracee’s ABI.

pub fn set_arg(&mut self, i: usize, v: u64)

Sets syscall argument i (0..6) in the register the tracee’s ABI uses.

pub fn sp(&self) -> u64

Current stack pointer.

pub fn ip(&self) -> u64

Current instruction pointer.

pub fn alloc_stack(&mut self, size: u64) -> u64

Reserves size bytes of scratch space below the tracee’s stack pointer.

The stack pointer itself is left untouched: we take no exit stop that could restore it, and the memory below sp minus the red zone is unused while the thread sits in the syscall instruction. (aarch64 has no red zone; skipping one is harmless.) Successive reservations stack downwards. For execve the kernel discards the whole stack anyway.

Arguments

• size - Bytes to reserve; the result is 16-byte aligned.

Returns

The address of the reserved block in the tracee.

pub fn commit(&self) -> Result<(), i32>

Writes the modified registers back if anything changed.

Trait Implementations

impl Clone for Regs

fn clone(&self) -> Regs

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.